Zheng is a vassal state in China during the Zhou Dynasty (1046–221 BCE) located in the center of ancient China in modern day Henan Province on the North China Plain about 75 miles (121 km) east of the royal capital at Luoyang.

It is the most powerful of the vassal states at the beginning of the Eastern Zhou (771-701 BCE).

Its ruling house has the surname Ji , making them a branch of the Zhou royal house, who were given the rank of BO, corresponding roughly to a Countdom.